Rated for the motor, not just the nameplate
The ABB PST37 1SFA895003R7000 is a soft starter sized for a 37 A in-line motor load — that's 18.5 kW on a 400 V three-phase supply. In an inside-delta configuration it handles 64 A and 30 kW, which is the wiring you'd use for a larger motor where the starter sits inside the delta loop to reduce the current through the main contacts. The main circuit is rated 400 to 690 V AC, so it covers standard European 400 V and 690 V industrial networks without a separate voltage tap. Built-in electronic overload protection is integrated — no separate overload relay needed in the panel. The current limit function is adjustable from 1.5 to 7 times the set motor current, which lets you tune the start for high-inertia loads or soft-coupled conveyors. Ramp time spans 0 to 120 seconds, with an initial voltage during start adjustable 30 to 70 % and a step-down special ramp from 100 to 30 %. That's enough range for most pump, fan, and compressor starts without external timers.
Control wiring and signals
Control supply voltage is 100 to 250 V AC, with a separate 24 V DC control circuit available for the logic. Screw terminals on the control circuit accept 1 x 2.5 mm² rigid; tighten to 0.5 N·m. The main circuit terminals accept 1 x 10 to 95 mm² rigid. Communication is via a standard FieldBusPlug — the PST37 accepts a plug-in fieldbus adapter, so you can add PROFIBUS, DeviceNet, or Modbus without changing the base unit. Four signal relays are built in: run, fault, by-pass, and overload. Each provides a dry contact for the PLC or status lamp. A red LED indicates a fault condition; a yellow LED signals protection activation. The analog output is 0 to 10 V, typically used to feed a speed or current signal to a remote meter or drive controller.